Recently, I wrote about my views on using and estimating with task-cards. I highlighted that tracking progress with burn-up/down charts showing effort completed/remaining is not a true measure of progress, especially if we subscribe to the idea that we measure progress with working-software.

I also highlighted how tasks “horizontally slice” a “vertically sliced” story.

This inspired an article on infoq by Mark Levison. Since its publication, there have been several comments.

There are some specific points I’ll be answering on infoq, but some general points are more easily answered here…

True measures of progress
One of the key points I was trying to make in my first post (linked to above) is that if “working software” is our measure of progress then tracking task completion is not consistent with that.

One of the problems task-hours are trying to solve is to provide a visible indication of progress. It’s also something that many people find easier to understand. The idea of relative-points estimation seems to baffle many people when they first encounter it.

In my original post (linked above) I referenced an approach, blogged about by Jason Gorman, outlining a solution to providing a visible indication of progress that is compatible with the idea of measuring progress with working software. It also works more seamlessly with the solution of measuring throughput trends of the team (e.g. with story points) so that the team can estimate how much can be done in the next iteration.

Value Points & Task Points
Value points were mentioned in the infoq comments. Value points are solving a different problem and don’t help the team estimate what can be done. The value of a story isn’t an indication of its complexity. Value, combined with complexity points, can help determine priorities. Arlo Belshey explains some interesting views on this.

Prioritisation is, in my view, one of the few reasons to place some sort of estimate on value & complexity. Unfortunately, it seems to be often used to establish a contract with the team for when something will be done and apply pressure when the estimates turn out to be inaccurate.

Non-estimating pull systems
My preference is to use such estimates only for prioritisation… after that, things just take as long as they take. There is some benefit in tracking accuracy trends so that we can learn from them, however, spending too much time on these things simply slows down the process of getting things done. Interestingly, I have not yet seen the business be quite so passionate about evaluating whether their value estimates were accurate when the product makes it to the real world. Funny that.

Instead, I prefer to leave estimation behind once we’ve prioritised things and pull stories or customer valued work items through the system without using previous estimates to predict their completion date. With the way that most budgets are determined and allocated, this idea isn’t compatible with the way much of the business world works. For pull systems that eliminate estimation as a means of predicting the future to work (such as Kanban), we need a more adaptive approach to budgetary spend. Business needs to find a way to adapt budget allocation more frequently, perhaps as frequently as monthly, perhaps more frequently still. The business now needs to look at how it can respond to change rather than focus on following a budget-plan.

Business-world: now it’s your turn
Budget holders now need to be more agile. We, those who evolve the implementation of the ideas of the business, have responded to their demands to be able to respond to rapidly changing markets and provide that competitive edge. For the more mature implementation teams, the hindrance now is no longer how we make the products, but the business culture of inflexible and predictive budget allocation.

Despite being completely wrong, the world forgot of my name’s etruscan origin and spelt it with an ‘H’… This misinformation established itself through the eras so much so that, today, the de-facto spelling is “Anthony”. It has even found it’s way into the American pronunciation of the name as: “An-thon-ee”.

Waterfall development has something in common with this story… somehow, through misinformation, what it once was has been warped, into something else.

The key difference is that Waterfall is now increasingly represented as was originally intended. Unfortunately for me, my name is not…

Monsters & Legends

This negative view, to what was once the de-facto approach to software development, is actually far closer to Royce’s original words on Waterfall than many seem to know…

The Truth & Technology

In Royce’s original paper, he shows a progression of activities, that came to be known as the waterfall model.

What we rarely hear of is Royce’s original words on the subject:

“…the implementation described above is risky and invites failure.”

Further to this, Royce goes on to explain that the reason that this cannot work is because there are too many things we cannot analyse up-front:

“The testing phase which occurs at the end of the development cycle is the first event for which timing, storage, input/output transfers, etc., are experienced as distinguished from analyzed. These phenomena are not precisely analyzable. They are not the solutions to the standard partial differential equations of mathematical physics for instance.”

He explains that we need feedback loops. He goes on to warn of (a conservative) 100% overrun in schedule and costs:

“…invariably a major redesign is required. A simple octal patch or redo of some isolated code will not fix these kinds of difficulties. The required design changes are likely to be so disruptive that the software requirements upon which the design is based and which provides the rationale for everything are violated. Either the requirements must be modified, or a substantial change in the design is required. In effect the development process has returned to the origin and one can expect up to a 100-percent overrun in schedule and/or costs.”

Some of Royce’s strategies, like “Involve the customer” and obtaining early feedback, have lived on in modern (Agile) methodologies. Beyond that, we should remember that his specific recommendations on how to solve the problems of a waterfall model were all based on the technology of the time.

Pot-Roast & The Cost of Change

In 1970, computing was much more expensive than it is today. In those days, changing software was far more expensive than changing pictures and words on paper. It was also much harder to express your design in a human-friendly way in the programming languages of that time. As a result of these and other factors, documentation was a major part of how Royce tried to solve the inherent problems of the Waterfall model.

Technology, tools & thinking have moved on and our documentation no longer needs to be static. It lives. It can breath. The specification can automatically verify that the implementation does what we said it should do (e.g. as in BDD Specs or ATDD/TDD Tests). Modern programming languages allow us to express the design and our understanding of the domain far more clearly, negating the need to first detail our thoughts on paper in natural language. We simply don’t have to cut the ends off that pot-roast anymore.

Only now, at the end…

Waterfall, thanks to the popularity of Agile, has gone from something I was shown at school as “how software is developed” to being seen in the light that it was originally presented – how software should not be implemented.

This is despite those who still profess the legitimacy of Waterfall and those still shocked and surprised when they hear of Royce’s own words against the monster he unintentionally created.

As for my name, I hold out little hope for change. I doubt that the world will use my name as it was originally intended and so I have resigned myself to needing two domain names… one with an ‘H’ in it, and the correct one without – I wonder which one brought you here.